TOKYO - Former U.N. weapons inspector Hans Blix said Friday that North Korea would one day master nuclear weapons technology despite its apparently less-than-successful atomic test, and he warned that the world must avoid striking a quick disarmament deal that lacks effective verification measures.

Blix said verification would be the key to ensuring compliance in any nuclear accord with Pyongyang, as the country returns to six-nation talks on its weapons program.

"I have no illusion it will be easy," he said.

President Bush, speaking Friday in Vietnam at the Asia-Pacific Economic Cooperation forum, urged other nations to take a tough line on enforcing U.N. sanctions against North Korea, adopted after the communist nation's Oct. 9 test that may have only partially detonated.

"It's important for the world to see that the Security Council resolutions which were passed are implemented" against North Korea, Bush said. "So part of my discussions will be how we fully implement those sanctions that the world has asked for."

North Korea is also taking a hard line in advance of the six-party talks on its nuclear arms programs, which will include the United States, Russia, China, the two Koreas and Japan. The North walked away from the negotiating table last year after the U.S. campaigned to cut off the North's access to foreign banks over alleged money laundering and counterfeiting.

Kim Myong Gil, deputy chief of North Korea's mission to the United Nations in New York, told The Associated Press that progress at the negotiating table depends on whether the United States "has a sincere attitude and has willingness to improve its relations" with his country, a signal North Korea is unlikely to make opening concessions.

Pyongyang's nuclear test triggered international condemnation and U.N. sanctions. Three weeks later, North Korea agreed to resume talks after Washington said it would discuss its financial sanctions.

Kim said that discussions on easing sanctions would make "a good start" for the talks, scheduled to resume in December.

Choe Thae Bok, the head of the North's rubber-stamp parliament, said in remarks reported Friday by the official Korean Central News Agency that Pyongyang remained committed to denuclearization through dialogue but that "it was compelled to conduct the nuclear test by the U.S."

Choe told a conference in Iran on Monday that the Bush administration bore the historic responsibility "for having torpedoed the process of denuclearizing the Korean Peninsula."

Washington, meanwhile, has said it agreed to consider easing sanctions only as a side issue to North Korea's nuclear disarmament.

In Japan, Blix said verification of North Korea disarmament would be especially tough given the secretive nation's history of restricting access by foreigners to much of the country. North Korea has limited the activities even of U.N. officials distributing food aid, he noted, and foreign weapons experts would likely be far less welcome.

The former chief weapons inspector warned against the temptation to sign a deal that doesn't guarantee full cooperation.

"Cosmetic inspection is worse than none because that can lull states into a confidence that is false, and you can have very unpleasant surprises" he said.

Blix, who questioned the Bush administration's assertions that Iraq had weapons of mass destruction before the war, noted that most experts believe North Korea's test was only a partial success because it produced a relatively small blast. But the world should not be "complacent" about North Korea's nuclear capability, he said.

"If they didn't succeed this time, how much time will it take them before they perfect it?" he said.

Blix called the Oct. 9 test was "a demonstration" of what the small, highly-militarized nation could ultimately achieve.

Blix was in Japan as part of an international tour to discuss recommendations from a report issued in June by the Weapons of Mass Destruction Commission, which he heads.

The 227-page report highlights the dangers of nuclear weapons and presented 60 steps that countries and disarmament organizations should take, mindful of a goal to one day ban and eliminate all nuclear arms.

"TerrorStorm is something that should be seen by everyone, no matter what their stance/affiliation/political bent. " - Rich Rosell, Digitally Obsessed UK Get TerrorStorm on DVD today